Several industry standards and federal regulations specify minimum acceptable efficiency of heating, ventilation, and air conditioning (HVAC) systems. Traditionally, HVAC system efficiency has been measured at full-load operating conditions. Efficiency at full-load operating conditions could be improved by adjusting the size of the condenser coils or the size of the compressor. Under current guidelines, however, more emphasis is placed on operating efficiency at part-load operating conditions. Thus, it becomes a challenge to increase efficient performance in an HVAC system that is already at maximum capacity. One approach is to utilize variable air volume designs in order to reduce air volume and power consumption during part-load operating conditions. However, it has been found to be cost prohibitive to retro-fit existing HVAC systems for variable air volume operation.